Serial number printing machines

ABSTRACT

Machine having means for printing serial numbers and means for printing check digits. The check digit printer is controlled by means including counting means having one counting unit for each digit of the serial number to be printed, the advancement of a counting unit transmitting pulses to operate the check digit printer. The means for controlling the check digit printer may be electromechanical or electronic. The counting units may be coldcathode gas filled decade counters.

United States Patent Wybrow et al. [451 Mar. 21, 1972 541 SERIAL NUMBERPRINTING 2,731,196 1/1956 Luhn ..235/6l.7 A

MACHINES 2,886,239 5/1959 Reumerman et al. 2,661,896 12/1953 [72]Inventors: Patrick S. Wybrow, Truro; Philip Muzlish, 2,731,201 1/1956North Harrow, both of England 2 75 7/1956 Assignee: said wy y saidMuzlish 3,448,254 6/1969 Verhoeff Filedl 1970 Primary Examiner-WilliamB. Penn [21] Appl No 13 936 Attorney-Watson, Cole, Grindle & Watson [57]ABSTRACT U.S. Cl. Machine having means for P g Serial numbers and means58] Field of Search C 72 235/61 7 for printing check digits. The checkdigit printer is controlled 5/61 7 A 92 by means including countingmeans having one counting unit for each digit of the serial number to beprinted, the advancement of a counting unit transmitting pulses tooperate the [56] References Cited check digit printer. The means forcontrolling the check digit UNITED STATES PATENTS printer may beelectromechanical or electronic. The counting units may be cold-cathodegas filled decade counters. 2,805,824 9/1957 Knutsen ..235/6l.7 A2,755,022 7/1956 Knutsen ..235/61.6 11 Claims, 2 Drawing Figures SERIALNUMBER PRINTING MACHINES This invention relates to machines for printingserial numbers. Printed serial numbers are required on many differenttypes of stationary such as vouchers, warrants, certificates, checks,payable orders and receipts. It is sometimes required to print inassociation with the serial number a so called random check digit whichis employed to enable the quotation of a serial number to be checked foraccuracy. Check digits are particularly valuable where the numbers areto be read by automatic means such as where the numbers are in magneticink and are read by a reader forming an input to a computer.

The check digit which is printed with the serial number is derived fromthe serial number by carrying out a number of predetermined arithmeticoperations on the digits of the serial number. Thus when a serial numberand random check digit are quoted later it is possible to perform thearithmetic operation on the digits of the serial number and compare theresult with the random check digit; if there is a difference either theserial number or the random check digit has been wrongly quoted. Ofcourse, the checking will normally be performed by the computer. Therandom check digit may be derived by multiplying each digit of theserial number by a predetermined multiplier, summing the results andsubtracting the units digit of the sum from a predetermined number. Itis found that by following this procedure with a series of numbers, therandom check digit follows a repeated sequence of the ten digits, fromzero to nine, (assuming that the said predetermined number is althoughnot necessarily in numerical order, but whenever there is a carry in theserial number e.g., when the serial number changes from nine to 10, from19 to 20, from 99 to I00, from 109 to 110, and so on) the random checkdigit sequence has a jump introduced into it. The jump may be of oneamount when the carry is from the units to the tens, another amount fromthe tens to the hundreds, another from the hundreds to thousands and soon, and in certain cases the jump may be zero, i.e., there in no advancein the random check digit sequence, or one, i.e., the random check digitadvances in unaltered sequence.

According to the present invention, a serial number printing machineincludes means for printing serial numbers and means for printing randomcheck digits, the means for printing random check digits comprisingcounting means having one counting unit for each digit of the serialnumber to be printed, which counting units are advanced in synchronismwith the corresponding digit printing devices of the printing mechanism,means associated with each counting unit arranged for the transmission,on advancement of the counting unit, of a predetermined number of pulsesto operate means for positioning the random check digit printer means inaccordance with the number of pulses transmitted to it, and selectionmeans for activating the transmission means associated with the highestof the counting units advanced during a serial number printing cycle.

The means for controlling the random check digit printer may be of anelectromechanical nature. Thus, in possible construction, the countingunits are cam wheels which are rotated in substantially the same manneras the discs of a normal counting box, the transmission means are camwheels mounted on a common shaft and controlling switching means forgenerating the pulses, and the selection means are switches controlledby the first cam wheels.

Preferably, however, electronic means are employed for controlling therandom check digit printer. Thus the counting means may compriseelectronic counting units such as cold cathode gas filled decadecounters. These may control displays such as neon number tubes so thatthe serial number being printed at any one time is visually indicated.

The control means may include a pulse generator and each transmissionmeans may be arranged to open a path for the passage of pulses from thepulse generator to the positioning means on advancement of theassociated counting unit until a predetermined number of pulses haspassed and then to close the path. The control means may include a pulsecounter and each transmission means may include a bistable arranged toclose the path after the pulse counter has counted the saidpredetermined number of pulses.

In a preferred arrangement, the selection means includes means fordeactivating a signal arising from each of the counting units beingadvanced other than the highest counting unit being advanced. Thedeactivation means may comprise, for each counting unit other than thehighest, an AND gate having an input connected to the output of each ofthe AND gates associated with the higher counting units. There ispreferably a delay element between each of the counting units except thehighest and its associated AND gate, the length of delay of the elementsdecreasing progressively from the lowest towards the highest countingunit.

The invention may be carried into practice in various ways and therandom check digit printer control system of one serial number andrandom check digit printer will now be described by way of example withreference to the accompanying diagrams, in which:

FIG. 1 shows the system and FIG. 2 is a detail of a signal generationsystem forming part of the system shown in FIG. 1.

The printer includes a standard numbering box (not shown) for printingthe serial number which, for convenience, will be assumed to consist ofsix digits. Each digit is printed by means of a numbering wheel in thebox and the control system includes an electronic counter consisting ofsix counting units A to A5 which operate in synchronizm with thenumbering wheels by means of a pulse fed over a signal input line B tothe counting unit A, each time the numbering box is advanced one unit.Each unit A -A is a decade counter arranged to deliver a pulse to theunit of the next highest order when it completes its own count of 10. Itwill be seen that the boxes representing the counting units have beenlabeled with the powers of ten corresponding to the values of the digitsof the respective numbering wheels. Clearly there may also besupplementary means for maintaining the individual counting units insynchronizm with the individual printing wheels so that they may both bepreset to any required number. Each of the counting units is coupled toa corresponding display-such as a neon number tube C C, so that thenumber being printed at any given time can be read from the display.Each time any of the counters A to A changes from one position to thenext position in synchronism with a corresponding change in thenumbering wheels in the numbering box, a pulse is delivered through acorresponding line D D to an AND gate E E Each of the lines D D,includes a delay element F F The amount of delay introduced decreasesprogressively from F to F The output from each AND gate goes to abistable G G and the outputs from all the bistables are connected asinputs to an OR gate H. The output from the bistable G is also connectedas an input to each of the AND gates IE E The output from the bistable Gis also connected as an input to each of the AND gates E E and similarlythe outputs of the bistables E to E, are connected as inputs to thelower AND gates. The output from the OR gate H forms one input to an ANDgate I the other input to which comes from a pulse generator J. Theoutput from the AND gate I passes through a pulse shaper K and anamplifier L to an output line M leading to the random check digitprinter. The random check digit printer includes a single numberedprinting wheel and a solenoid-operated pawl and ratchet mechanismarranged to advance the printing wheel by one position for each pulsesupplied to it along the line M. The line M also leads to a random checkdigit display N alongside the displays the displays C C so that therandom check digit being printed is displayed alongside the serialnumber being printed.

The components D F E G H, I, J, K, L, and M, constitute a transmissionmeans associated with the counter A for controlling the supply of pulsesto the mechanism 14 when the unit A is advanced.

The output from the pulse shaper K also passes to a four digit binarycounter 0 which, by a system D which is shown in FIG. 1 partly in blockform and which comprises a number of AND gates which will be describedin detail below, transmits reset pulses to socket outlets Q, to O in apatch board. After the counter has counted one pulse a reset pulse istransmitted to outlet (2,, after two pulses to outlet 0, and so on. Theresetting input of each of the bistables G G is connected to one of theoutlets Q, to Q For example, the reset terminal R and R, of thebistables G and G, might be connected to the outputs Q and Q, asindicated by dotted lines in FIG. 1.

Operation of the system is as follows. When a pulse is fed into thecounter through the line B and the counter unit A is the only unit tochange, a pulse will be delivered along the line D through the delay Fto the AND gate E The AND gate E is arranged to conduct when a pulse isreceived through the line D and when the signals received from thebistables G, G are of the kind indicating that those bistables are intheir normal states. Accordingly, the AND gate E conducts and thebistable G is triggered to its other state. The OR gate H is arranged toconduct when one of its inputs is an output from a bistable in its otherstate. Accordingly, the OR gate H conducts and a signal is passed to theAND gate l which opens to pass pulses from the pulse generator to theoutput line M. The pulses passed are also counted by the binary counterO which, when it has counted three pulses, passes a signal to the outputterminal 0,, which passes along the reset line R to reset the bistable GThis closes the gates H and 1. Three pulses will have been passed alongthe output line to the random check digit printer which will have beenadvanced by three units.

If the input pulse along the line B causes the counting unit A, to movefrom 9 to 10, the counting unit A, also will be advanced by one unit andsubstantially simultaneous pulses will pass along the lines D, and D,.The time delay introduced by the delay F, is shorter than thatintroduced by the delay P, so the signal from unit A, reaches the ANDgate E, before the signal from A reaches the AND gate E Accordingly, thebistable G, is triggered to its other state and the output from thisbistable will form an input to the AND gate E preventing the AND gate Eopening. The output will also open the gates H and l which will remainopen until the binary counter 0 has counted five pulses and a resetsignal has been passed through 0, and R, to reset the bistable G,, i.e.,to act with the bistable associated with the highest of the countingunits. At the same time five pulses will have been passed through theoutlet line M to advance the random check digit by five positions.

In a similar way, when any of the higher counting units A, to A isadvanced by one unit the AND gates of the lower counting units will berendered nonconductive by the output from the bistable of the highestcounting unit advanced since the signal to this bistable is delayed by ashorter time than the signals to the lower bistables.

The system D for transmitting reset pulses to the bistables which isbriefiy referred to above is shown in more detail in FIG. 2 which showsthe components necessary for outputs after each pulse received by thebinary counter up to six. The components necessary for outputs aftercounts of seven, eight and nine as indicated in FIG. 1 will easily beunderstood when reference has been made to FIG. 2. The system comprisessix AND gates S and their connections to the appropriate outputterminals of the binary counter 0.

In order to be able to select any number up to nine for any of the sixbistables, six separate systems P would be necessary to accommodate thecase in which each bistable is to be reset after the same number ofpulses, To avoid this it is possible to provide a supply of plug-ingating systems for counting various numbers of pulses and to select foreach bistable an appropriate system which is plugged into the binarycounter and to which the reset input of the bistable is connected.

While the invention has been described in connection with the preferredembodiment, it will be understood that it is not limited to thatdescribed. Accordingly, the invention is intended to cover allalternatives, modifications and equivalents as may be included withinthe scope and spirit of the invention as defined by the followingclaims.

What we claim as our invention and desire to secure by Letters Patentis:

1. In a printing machine having means for printing a sequence of serialnumber digits and means for printing a check digit associated with eachserial number, control means comprising:

means for computing said check digits for each said serial number as itis printed, said means including multi-unit counting means having onecounting unit for each digit of said printed serial number,

means for advancing said counting units in synchronization with theoperation of said serial number digit printing means, means foradvancing the individual check digits in accordance with the state ofsaid multi-unit counting means;

means for transmitting from each counting unit a predetermined number ofpulses to said means for advancing said check digits, and

means for selecting an individual transmission means associated with themost advanced of said counting units in a serial number printing cycle.

2. The printing machine as set forth in claim 1 wherein said countingunits are electronic counting units.

3. The printing machine as set forth in claim 2 wherein said countingunits are cold-cathode gas-filled decade counters.

4. The printing machine as set forth in claim 2 further comprising avisual display controlled by each of said counting units for indicatingthe number held by each said counting unit.

5. The printing machine as set forth in claim 1 further com prising apulse generator and wherein each transmission means provides a path forthe passage of pulses from said pulse generator to said means foradvancing the individual check digits with the advancement of theassociated counting unit until a predetermined number of pulses haspassed and said transmission means opening said path.

6. The printing machine as set forth in claim 5 further comprising apulse counter and wherein each transmission means includes a bistablecircuit for interrupting said path after the pulse counter has countedthe said predetermined number of pulses.

7. The printing machine as set forth in claim 6 further comprising aplurality of AND gates and wherein said pulse generator and each of saidbistable circuits is connected to an AND gate having an output connectedto said means for advancing the individual check digits.

8. The printing machine as set forth in claim 7 further comprising an ORgate and wherein said bistable circuits are connected to said AND gatethrough said OR gate.

9. The printing machine as set forth in claim 1 wherein said selectionmeans includes means for deactivating a signal from each of saidcounting units other than said most advanced counting unit.

10. The printing machine as set forth in claim 9 wherein saiddeactivation means comprises, for each counting unit other than thehighest order counting unit, an additional AND gate having an inputconnected to the output of each of said AND gates associated with thehigher counting units.

11. The printing machine as set forth in claim 10 further comprising adelay element between each of said counting units and its associated ANDgate with the exception of the highest order counting unit, the lengthof delay of said elements decreasing progressively from the lowesttowards the highest counting unit.

1. In a printing machine having means for printing a sequence of serialnumber digits and means for printing a check digit associated with eachserial number, control means comprising: means for computing said checkdigits for each said serial number as it is printed, said meansincluding multi-unit counting means having one counting unit for eachdigit of said printed serial number, means for advancing said countingunits in synchronization with the operation of said serial number digitprinting means, means for advancing the individual check digits inaccordance with the state of said multi-unit counting means; means fortransmitting from each counting unit a predetermined number of pulses tosaid means for advancing said check digits, and means for selecting anindividual transmission means associated with the most advanced of saidcounting units in a serial number printing cycle.
 2. The printingmachine as set forth in claim 1 wherein said counting units areelectronic counting units.
 3. The printing machine as set forth in claim2 wherein said counting units are cold-cathode gas-filled decadecounters.
 4. The printing machine as set forth in claim 2 furthercomprising a visual display controlled by each of said counting unitsfor indicating the number held by each said counting unit.
 5. Theprinting machine as set forth in claim 1 further comprising a pulsegenerator and wherein each transmission means provides a path for thepassage of pulses from said pulse generator to said means for advancingthe individual check digits with the advancement of the associatedcounting unit until a predetermined number of pulses has passed and saidtransmission means opening said path.
 6. The printing machine as setforth in claim 5 further comprising a pulse counter and wherein eachtransmission means includes a bistable circuit for interrupting saidpath after the pulse counter has counted the said predetermined numberof pulses.
 7. The printing machine as set forth in claim 6 furthercomprising a plurality of AND gates and wherein said pulse generator andeach of said bistable circuits is connected to an AND gate having anoutput connected to said means for advancing the individual checkdigits.
 8. The printing machine as set forth in claim 7 furthercomprising an OR gate and wherein said bistable circuits are connectedto said AND gate through said OR gate.
 9. The printing machine as setforth in claim 1 wherein said selection means includes means fordeactivating a signal from each of said counting units other than saidmost advanced counting unit.
 10. The printing machine as set forth inclaim 9 wherein said deactivation means comprises, for each countingunit other than the highest order counting unit, an additional AND gatehaving an input connected to the output of each of said AND gatesassociated with the higher counting units.
 11. The printing machine asset forth in claim 10 further comprising a delay element between each ofsaid counting units and its associated AND gate with the exception ofthe highest order counting unit, the length of delay of said elementsdecreasing progressively from the lowest towards the highest countingunit.